Plans to use an Italian port as part of a process to destroy Syrian chemical weapons have stumbled over local opposition, raising the risk of delaying the U.S.- Russia sponsored project to eradicate a trove that includes mustard gas and components of sarin gas.

The opposition in Italy marks the latest chapter in a process plagued by safety concerns. The issue of where to destroy Syria’s chemical weapons has been challenging since experts concluded late last year it would be too dangerous to do it in Syria in the midst of a civil war there.

The first consignment of chemicals was loaded onto a Danish ship several days ago, and the vessel is waiting for more batches to reach the Syrian port. It will be loaded with 560 metric tons of chemicals in the Syrian port of Latakia, including mustard agent and the sarin precursor DF. Then it should sail to the Italian port, where the materials would be transferred to a U.S. ship.